Protection device for an injection needle with a curved tip

ABSTRACT

A protection device for a needle with a curved tip ( 7 ) is provided, comprising a tubular part ( 20 ) which can be moved along the needle shank ( 6 ) and from which at least one elastic arm ( 30 ) protrudes in the axial direction in such a way that the free end of said arm bears, with pretensioning, on the needle shank and, upon reaching the needle tip, engages over and covers the latter, said tubular part ( 20 ) being configured in such a way that it cannot be pushed over the curved needle tip ( 7 )

SUMMARY OF THE INVENTION

[0001] The invention relates to a protection device for an injection needle with a curved tip, for example an epidural needle, a Huber needle or the like.

[0002] For giving injections, it is known in the medical field to use what are called Huber needles whose tip is slightly curved so that the mouth of the hollow needle lying obliquely with respect to the needle axis lies substantially parallel to the needle axis. In this way it is possible to introduce the injection needle into part of a patient's body through a fabric, without the open needle tip becoming clogged by the material of the fabric, because the plane of the needle mouth lies in the axial direction of the needle, which direction corresponds to the injection direction.

[0003] Moreover, it is known to provide injection needles with a protection device by means of which the needle tip is covered after the needle has been withdrawn from a patient's skin, so that the person giving the injection cannot be injured by the needle tip, thereby avoiding infection, for example by hepatitis or AIDS. In the case of straight injection needles, various designs of protection devices used for this purpose are known.

[0004] The object of the invention is to provide a protection device for a needle with a curved tip, which device is of simple construction and in particular can be easily produced.

[0005] According to the invention, this object is achieved by the features described in claim 1. By providing a tubular portion which can be moved along the needle shank and from which at least one elastic arm protrudes in the axial direction of the needle in such a way that said arm bears, with pretensioning, on the needle shank and, upon reaching the needle tip, engages over and covers the latter, this needle protection device can be easily produced from, for example, a strip of metal, for instance by punching out and bending.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Illustrative embodiments of the invention are explained in more detail below with reference to the drawings, in which:

[0007]FIG. 1 shows, in a plan view, a punched-out sheet of metal and a protection device formed from this,

[0008]FIG. 2 shows, in the same view as in FIG. 1, a punched part and the protection device with two arms formed from this,

[0009]FIG. 3 shows the arrangement of the protection device according to FIG. 2 on a needle,

[0010]FIG. 4 shows the protection device in the protection position on the needle tip, and

[0011]FIG. 5 shows a further embodiment of a punched part.

DETAILED DESCRIPTION OF THE INVENTION

[0012]FIG. 1a shows, in a plan view a flat piece 1 which has been punched out from a sheet of metal and is, for example, approximately T-shaped with an approximately rectangular portion 2 from which a likewise approximately rectangular portion 3 protrudes approximately at right angles.

[0013]FIG. 1b shows the protection device which has been formed from this flat piece 1 and in which the rectangular portion 2 is bent to form a tubular part 20 so that the end edges of the portion 2 lie opposite one another along a gap 4. The elastic arm 30, formed by the portion 3, of the protection device has an end 5 which is curved or angled in relation to the longitudinal axis of the tubular part 20 and whose edge is preferably bent inward. This configuration of the arm 30 with curved end 5 can be preformed, during the punching operation, by shaping in a punch mold before the portion 2 is made tubular.

[0014]FIG. 2a shows a flat piece 1 from whose rectangular portion 2 two portions 3 and 3′ protrude approximately at right angles, at a distance from one another. Here, the portion 3′ is slightly longer than the portion 3. Moreover, in this illustrative embodiment, the portion 3 is designed in continuation of the end face of the rectangular portion 2.

[0015] A protection device formed from this flat piece is represented in FIG. 2b. The distance between the two portions 3 and 3′ is chosen in such a way that, after the portion 2 has been bent to give a tubular part 20, the portions forming the arms 30 and 30′ of the protection device lie diametrically opposite one another. In this configuration too, the free ends of the arms are preferably curved inward, said free ends of the arms 30 and 30′ being offset relative to one another as a result of the different length of the corresponding portions of the flat piece 1, as can also be seen from FIGS. 3 and 4.

[0016] The arms 30 of the protection device are of planar configuration. FIGS. 1b and 2 b show a transition area 40 from the curvature of the tubular part 20 to the flat arm 30, since only a flat arm is elastic in the radial direction, so that the arm can bear with pretensioning on the needle shank and, on reaching the needle tip, can spring back into the protection position, as is illustrated in FIGS. 3 and 4.

[0017]FIG. 3 shows the protection device 1 according to FIG. 2b on the shank 6 of the needle, which has a curved tip such that the plane of the mouth 8 lies substantially parallel to the longitudinal axis of the needle At the opposite end of the needle there is a cannula attachment 9 via which the needle can be fitted to a syringe. The tubular part 20 of the protection device can be moved along the needle shank 6, and the arms 30 and 30′ lying opposite one another bear with elastic pretensioning on the needle shank. The internal diameter of the tubular part 20 is chosen in relation to the external diameter of the needle shank 6 so that the protection device an be easily moved along the needle shank 6 but cannot be pushed over the curved tip 7. In the starting position according to FIG. 3, the protection device is expediently situated in the area of the cannula attachment 9. When the needle is withdrawn from the patient's skin after an injection has been given, the protection device can be held in one hand via the tubular part 2, while the needle is pulled back using the other hand. In so doing, the protection device is moved to the protection position represented in FIG. 4, in which position the arms 30 and 30′, because of their elastic pretensioning, spring back in the direction toward the needle axis and in so doing cover the needle tip. As a result of the different length of the arms, their free ends engage over one another, so that the needle tip is covered and the risk of injury excluded.

[0018] In this protection position or covered position, the protection device can no longer be moved back to the starting position in FIG. 3, because the inwardly angled or rounded ends of the arms engage over the needle tip and prevent rearward movement. Moreover, the protection device cannot be moved beyond the needle tip because the tubular part 20 is configured in such a way that it cannot be pushed over the curved tip 7.

[0019] Various modifications of the described embodiments are possible. Thus, the end edges of the portion 2 of a flat piece 1 can also overlap or bear on one another after they have been bent to give a tubular part 20.

[0020]FIG. 5 shows a modified embodiment in which the portions of the flat piece 1 which form the arms 30 of the protection device are designed in an approximate T-shape with a narrow bridge 10 issuing from the portion 2 and with a widened head portion 11 at the free end. During production, the narrow bridge portion 10 facilitates an elastic design of the arm, while the portion 2 of the flat piece 1 is bent to give the tubular part 20. Here, once again, the two arms are expediently designed with different lengths in order to ensure that they reliably engage over the needle tip.

[0021] According to a further embodiment, three arms can also be provided, offset relative to one another in the circumferential direction, on the circumference of the tubular part 20, in which case three portions 3 issuing at intervals from the portion 2 are provided on a flat piece 1.

[0022] Upon assembly, the protection device 1 can be pushed onto the end remote from the tip before the cannula attachment 9 is applied.

[0023] The flat pieces 1 represented in FIGS. 1, 2 and 5 can also have arm portions 3 and 10 issuing obliquely from the rectangular portion 2, in which case the two arms can be fitted obliquely in opposite directions.

[0024] The flat pieces 1 forming a protection device can be easily and quickly produced for example from a metal strip by punching and subsequent shaping. It is also possible to produce a protection device 10 with a tubular portion 20 and with at least one arm 30 formed integrally thereon, for example by injection-molding from a suitably stiff and elastic synthetic material. 

What is claimed is:
 1. A protection device for a needle with a curved tip (7), comprising a tubular part (20) which can be moved along the needle shank (6) and from which at least one elastic arm (30) protrudes in the axial direction in such a way that the free end of said arm bears, with pretensioning, on the needle shank and, upon reaching the needle tip, engages over and covers the latter, said tubular part (20) being configured in such a way that it cannot be pushed over the curved needle tip (7).
 2. The protection device as claimed in claim 1, which device is formed from a flat piece (1) of elastic material, in particular from a metal sheet, where a rectangular portion (2) of the flat piece is bent to form the tubular part (20), and a portion (3), protruding from the portion (2) of the flat element, forms an arm (30) of the protection device.
 3. The protection device as claimed in claim 2, where the flat piece (1) has portions (3) of different length which protrude transversely from the approximately rectangular portion (2).
 4. The protection device as claimed in claims 2 and 3, where the portions protruding transversely from the rectangular portion (2) have a narrow bridge portion (10) with a widened head portion (11).
 5. The protection device as claimed in claims 2 through 4, where the arms (30) are of planar configuration and merge via a transition area (40) into the tubular part (20). 